Conventionally, when changing the condition of the apparatus due to the difference in use environment (region) or changing the setting value in recovery operations, a serviceman confirms a corresponding setting item code by reference to a manual, inputs the setting item code and adjusts a setting value, or inputs a setting item code stored as an empirical value to change a setting value.
Through digitization, colorization, diversification, colorized or multi-functionalized, the number of the setting item code as an adjustment object of the setting value in the image forming apparatus is on the increase, the number of the code are increased from hundreds reach thousands. Thus, it is extremely difficult for the serviceman to remember all the code numbers. Consequentially, in adjusting a setting value, the serviceman needs to refer to a manual to confirm a code number for an adjustment.
However, there are so many setting item codes which are all different in value range that sometimes a value beyond a normal action range is set.